This invention relates to a composite material having improved wear- and impact-resisting properties and a process for the production of same.
In the fields of mining, civil engineering and construction, cememt, and iron industries, it is general that cast steel parts used for machine apparatus and other industrial facilities are required to have an excellent resistance to impact and as well as a resistance to wear.
Wear-resisting cast steel parts have been heretofore made of high chromium cast iron, high manganese cast steel, high chromium cast steel, low alloy steel, etc. However, these materials have some drawbacks that they are poor in either toughness or wear-resisting property. A material which shows both toughness and wear-resisting property has not been found yet. Therefore, the cast steel should be properly selected depending on the purpose in end use. To cope with this problem, there has been proposed a composite material composed of two kinds of materials with different mechanical properties. As shown in FIGS. 1-A and 1-B, for example, there is known a composite material which includes a base metal 1 having high toughness and a plurality of highly hard steel ingot blocks 2. The composite material is excellent in toughness and wear-resisting property and can be used as, for example, an impact plate for grinder or crusher for lubricant-free soil and sand, stones and rocks, etc. However, since fixing of the plurality of highly hard blocks 2 to the base metal 1 is made by a method using adhesives, a method using bolted connections or a method using brazing, such composite material has the following drawbacks. A composite material produced by using adhesives must be used within a limited temperature range. Blazing method is disadvantageous in that fixing of blocks to a base metal must be made at limited portions. The bolt connection presents a problem that the highly hard block is almost impossible to be tapped. If bolts have been previously incorporated into the block, there is a danger that the block is to break or crack. Further, to attach bolts requires additional steps and is thus disadvantageous in economy.